Kevlar thread

[webphut]

Hello all,

I am new and this is my first post. I have been reading the forums for about a week or so and I like so far what I have read. Anyways...

I am going to start learning how to sew leather. I did spend about 2 hours hand stitching , but after two hours, I was just so ready to quit. I am buying a  used sailrite leatherwork sewing machine on Saturday mornng. For my first project I will be attempting to make a welding apron. It will be 3 to 4 oz suede with crossback leather straps. I plan to have two chest pockets and thats probably about it until I get more comfortable with sewing leather. I planned to use kevlar thread to sew the apron together with because of the sparks from grinding and welding. As for the kevlar, How do I end the threads  after I cut away from the sewing machine? Do I just re thread it back into the existing holes where the thread has previously gone? I know that usually melting the thread ends is the goto standard, but kevlar does not exactly melt, which is why I chose to use it on a welding apron. Should i just use the regular nylon or polyester thread? Also, I am getting the vibe from what I have read thus far tex90 or thread size 92 is the norm for these type of projects. 

I look forward to reading the repsonces. Thank you for your time.

 

[TomE]

Welcome.  I don't have experience with Kevlar thread but learned a fair amount by searching the forums.  From what I read, I'd be reluctant to run abrasive Kevlar thread through my machine and also deal with the tensioning issues unless it's absolutely needed.  I imagine most of the stitching will be along edges and the back of the apron, so not directly in the line of fire.(?)  Not sure what type of leather you're using but #92 thread seems a bit small to me.  I recently repaired a farrier's apron (chaps) made of 5-6 oz chrome tanned leather and used #138 nylon thread that was a good match with existing.  The thighs are covered with reinforcing patches of 6oz secured with 2 lines of stitching.  Double stitched might be a useful failsafe for a welding apron.      

[kgg]

1 hour ago, webphut said:

I am buying a  used sailrite leatherwork sewing machine on Saturday mornng.

The Sailrite Leatherwork from a thread size will be limited to V92 thread and without modifications the max sewing thickness will be limited to something less then 1/4". Their spec from their site "You can use thread up to V-92 (Tex 90) and needles up to #22 with this machine, although we recommend V-92 Polyester and #20 DI Leather Needles for most applications. " Note that V92 bonded polyester thread is a thinner and softer then V92 bonded nylon.

A couple of points about this machine:

i) This is a walking foot machine not a compound feed machine. It is classed as a heavy duty not a industrial sewing machine. My opinion is that it is a notch up from a domestic sewing machine.

ii) the Leatherwork is just a portable walking foot Sailrite LS model painted green and placed in nice short table with a good servo motor.

iii) be aware with the portable walking foot machines as the thickness of the material increases like across multi layers the stitch length decreases. On my Sailrite LSZ clone, which is setup for binding, I did manage to get the height clearance under the outer and inner presser feet up to 10mm (touch over 3/8") with a few fancy words of encouragement while making adjustments. Before it was under 1/4 " (6.35mm). The original stitches were 8.5 on a a touch over 1/4" (7mm) thickness of material. With the adjustments I made to the machine it gets 5 on 7mm thick material and on a normal couple layers of cotton fabric I can get it down to 3.5 stitches per inch.

ii) the original intent of the portable walking foot machines was to sew sail fabric.

iii) Sailrite customer service has a good reputation.

If you plan on getting into sewing leather or heavier fabric there are better options both in the new and used machines.

Kevlar thread is going to be hard on the guides and tensioning parts as it is quite abrasive. You may even have to go down to size V69 thread to get it to sew properly in the Leatherworker.

1 hour ago, webphut said:

Also, I am getting the vibe from what I have read thus far tex90 or thread size 92 is the norm for these type of projects. 

Personally I would use size V138 or V207 for durability and strength particularly for pockets that you are going to be tugging on a lot. Size V69 thread has a breaking strength of 11 lbs, V92 is 14.5 lbs, V138 is 22 lbs and V207 is 32 lbs.

How much are they asking for the Sailrite Leatherwork???  Any photo's???

kgg

 

 

Edited May 5, 2023 by kgg

[webphut]

Ok, that is golden information. Thank you. I will pass on the Sailrite leatherwork then. Sounds like I need to keep looking for a industrial walking foot sewing machine or one with compound feed. 
Im glad I got some input and I can still pass on the sewing machine. Probably saved me a few hundred dollars or maybe even a grand. Ok thank you.

[Tugadude]

Personally I urge you to reconsider stopping hand stitching after 2 hours.  It is a skill, a skill which takes time to develop, but when you acquire it, you will find that it is manageable.  I only hand stitch, mainly because I am a hobbyist and don't feel the need to purchase a machine.  I also don't care for some of the product I see which is machine sewn.  I said some, not all, so please don't think I'm saying I'm against using a machine.  It just isn't for me.  

With time and effort, I can now stitch pretty fast, fast enough for me anyway.  And I enjoy it.  Much of the pleasure I derive from the craft is the stitching itself. 

If you want a machine, by all means go for it, but please give hand stitching more time.  I think it will be worth it.

Edited May 5, 2023 by Tugadude

[webphut]

26 minutes ago, Tugadude said:

Personally I urge you to reconsider stopping hand stitching after 2 hours.  It is a skill, a skill which takes time to develop, but when you acquire it, you will find that it is manageable.  I only hand stitch, mainly because I am a hobbyist and don't feel the need to purchase a machine.  I also don't care for some of the product I see which is machine sewn.  I said some, not all, so please don't think I'm saying I'm against using a machine.  It just isn't for me.  

With time and effort, I can now stitch pretty fast, fast enough for me anyway.  And I enjoy it.  Much of the pleasure I derive from the craft is the stitching itself. 

If you want a machine, by all means go for it, but please give hand stitching more time.  I think it will be worth it.

Like you, I actually like the actual stitching part of hand stitching. That was actually what got me into it. I think really what I need, to keep me interested in hand stitching, is a faster way to punch all the holes for the thread.

[Burkhardt]

5 minutes ago, webphut said:

Like you, I actually like the actual stitching part of hand stitching. That was actually what got me into it. I think really what I need, to keep me interested in hand stitching, is a faster way to punch all the holes for the thread.

You can get a set of cheap stitching chisels off of Ebay or Amazon for 10.00 for a set of 4. 4mm is pretty universal size.

[kgg]

12 minutes ago, webphut said:

I think really what I need, to keep me interested in hand stitching, is a faster way to punch all the holes for the thread.

A thought maybe using a punch press / drill press where you can install various chisels to punch the holes with less effort.

kgg

[fredk]

26 minutes ago, webphut said:

Like you, I actually like the actual stitching part of hand stitching. That was actually what got me into it. I think really what I need, to keep me interested in hand stitching, is a faster way to punch all the holes for the thread.

These;

really speed up the hole punching

[fredk]

Tandy does an adapter set for their press to use their multiple change stitching holes punches

these punches;

https://www.tandyleather.world/products/diamond-hole-chisel-set

this press

https://www.tandyleather.world/products/tandypro-r-hand-press?_pos=5&_sid=8ee07cb9c&_ss=r

or

https://www.tandyleather.world/products/craftool-hand-press?_pos=1&_sid=8ee07cb9c&_ss=r

this adapter

https://www.tandyleather.world/products/press-die-for-hand-press-diamond-chisel?pr_prod_strat=use_description&pr_rec_id=c6c0b3465&pr_rec_pid=6614473965703&pr_ref_pid=6614474064007&pr_seq=uniform